There have been various different types and kinds of full color video display systems. Inventive techniques for producing such a full-color display include the use of direct view video or television monitors.
While such techniques have been satisfactory for some applications direct video and television monitors have generally limited with respect to the size of the viewed video image, due to the limited screen area associated with the cathode ray tube employed by such monitor units. Moreover, such systems have been relatively expensive to manufacture, as a result of the cost associated with the direct view video monitors.
Therefore, it would be highly desirable to have a new and improved full-color display system that can produce for a user or audience a large television image, without employing an expensive direct view television monitor.
One attempt to over come the problem of having a limited viewing area has been to employ a rear view projection system where a television signal is converted into its component color parts of red, green and blue to drive a set of red, green and blue lights which are projected onto the rear side of a large transparent screen for viewing purposes. While this technique has proven to be satisfactory for some applications, it has proven to be relatively expensive and requires a large cumbersome display unit cabinet which is difficult to move from place to place. In addition, the brightness of the viewed images is somewhat impaired because of the loss of light in traversing the transparent screen.
Therefore, it would be highly desirable to have a new and improved video display system for displaying large color images produced from a television signal which would be relatively inexpensive and that would not be difficult to move from place to place for viewing purposes.
Another attempt to overcome the problem associated with poor luminance in a large screen viewing system, has been to employ a direct front projection system. The direct projection system is similar to the rear view system except that the red, green and blue lights are projected onto the front surface of a large reflective screen from a projection unit disposed in front of the screen. Again, while such a technique has proven satisfactory for some applications, it has not proven entirely satisfactory, since the projection unit has typically been mounted in a permanent location relative to the screen, for proper focusing and to assure that a sufficient amount of light is projected onto the screen to provide an image with sufficient brightness for viewing purposes.
Therefore, it would be highly desirable to have a new and improved video display system, which could produce large screen viewing images having a relatively high luminance level and which would not be required to be permanently mounted or otherwise positioned.